In many communication applications and installations, a card cage is used to house a number of communication modules. A card cage typically has a main circuit board, referred to as a “backplane” to which the communication modules electrically connect. While it may not be desirable for every communication module to connect to the backplane for operational purposes, it is desired that each communication module connect to the backplane, at least to communicate the presence of the communication module to the system and for inventory purposes. Each communication module may be one of a similar type of module, or each communication module may be different from an adjoining communication module. Moreover, it may be desirable to have the ability to connect similar communication modules to different card cage and backplane form factors having different mechanical configurations. This frequently occurs where it is desirable to use a standard communication module for a number of different form factor applications. In such instances, an adapter may be used to allow the communication module to connect to more than one card cage and backplane configuration.
An example of a communication module is a passive optical module (POM). In some applications, it is desirable to have the ability to install a POM in at least two or more different systems. However, often the two systems are not mechanically identical, and in particular, may not have the same depth. An adapter/extender could be implemented and attached to the POM, but such a solution adds cost, complexity, and increases chances for misalignment of the communication module within the card cage.
Therefore, it would be desirable to have a way of installing a communication module in two or more systems having different form factors.